CVE-2002-0639

CVE-2002-0639 is a critical-severity vulnerability in Openbsd Openssh with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 18% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-190.

Key facts

Description

Integer overflow in sshd in OpenSSH 2.9.9 through 3.3 allows remote attackers to execute arbitrary code during challenge response authentication (ChallengeResponseAuthentication) when OpenSSH is using SKEY or BSD_AUTH authentication.

Frequently asked questions

What is CVE-2002-0639?
Integer overflow in sshd in OpenSSH 2.9.9 through 3.3 allows remote attackers to execute arbitrary code during challenge response authentication (ChallengeResponseAuthentication) when OpenSSH is using SKEY or BSD_AUTH authentication.
How severe is CVE-2002-0639?
CVE-2002-0639 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2002-0639 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 18% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2002-0639?
CVE-2002-0639 affects Openbsd Openssh. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2002-0639?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2002-0639 published?
CVE-2002-0639 was published on 2002-07-03 and last updated on 2026-06-16.

References

Affected products (1)

More vulnerabilities in Openbsd Openssh

All CVEs affecting Openbsd Openssh →

Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

Browse all CWE-190 (Integer Overflow or Wraparound) vulnerabilities →